smurf: Only switch off wcs wrapping for tiles that straddle RA=12h

applications/smurf/libsmf/smf_jsadicer.c

@@ -101,6 +101,10 @@
 *        the bounding box of each tile in the output NDF. This is to
 *        avoid tailes that span RA=12h being wrapped round to the far
 *        side of the projection, thus producing a huge box.
+*     30-SEP-2014 (DSB):
+*        Only disable lon/lat wrapping for tiles that span RA=12h. The 
+*        other tiles in the split HPX facet require lon/lat wrapping to 
+*        be on, in order to work properly.
 *     {enter_further_changes_here}
 
 *  Copyright:
@@ -481,25 +485,39 @@ void smf_jsadicer( int indf, const char *base, int trim, smf_inst_t instrument,
 
 /* Next job is to find the pixel bounds of the output NDF to create
    which will hold data for the current tile. First map the pixel bounds
-   of the whole tile from output to input. Because of the jagged
-   discontinuity at RA=12 h in the HPX all-sky projection, we need to
-   disable wrapping of WCS values qwithint he WcsMap class temporarily. */
+   of the whole tile from output to input. */
       lbnd_in[ 0 ] = tile_lbnd[ 0 ] - 0.5;
       lbnd_in[ 1 ] = tile_lbnd[ 1 ] - 0.5;
       lbnd_in[ 2 ] = lbnd[ 2 ] - 0.5;
       ubnd_in[ 0 ] = tile_ubnd[ 0 ] - 0.5;
       ubnd_in[ 1 ] = tile_ubnd[ 1 ] - 0.5;
       ubnd_in[ 2 ] = ubnd[ 2 ] - 0.5;
-      old_wrap = astGetWcsWrap;
-      astSetWcsWrap( 0 );
+
       astMapBox( p2pmap, lbnd_in, ubnd_in, 0, 1, lbnd_out + 0,
                  ubnd_out + 0, NULL, NULL );
       astMapBox( p2pmap, lbnd_in, ubnd_in, 0, 2, lbnd_out + 1,
                  ubnd_out + 1, NULL, NULL );
       if( ndim == 3 ) astMapBox( p2pmap, lbnd_in, ubnd_in, 0, 3,
                                  lbnd_out + 2, ubnd_out + 2, NULL,
                                  NULL );
-      astSetWcsWrap( old_wrap );
+
+/* Tiles that straddle RA=12h will produce very big bounding boxes
+   because half of the tile will be wrapped round to the other side of the
+   all-sky grid. Test for this, and if found, re-calculate the bounding
+   boxes without wrapping WCS values within the WcsMap class. */
+      if( ubnd_out[0] - lbnd_out[0] > 10000 ||
+          ubnd_out[1] - lbnd_out[1] > 10000 ) {
+         old_wrap = astGetWcsWrap;
+         astSetWcsWrap( 0 );
+         astMapBox( p2pmap, lbnd_in, ubnd_in, 0, 1, lbnd_out + 0,
+                    ubnd_out + 0, NULL, NULL );
+         astMapBox( p2pmap, lbnd_in, ubnd_in, 0, 2, lbnd_out + 1,
+                    ubnd_out + 1, NULL, NULL );
+         if( ndim == 3 ) astMapBox( p2pmap, lbnd_in, ubnd_in, 0, 3,
+                                    lbnd_out + 2, ubnd_out + 2, NULL,
+                                    NULL );
+         astSetWcsWrap( old_wrap );
+      }
 
       lbnd_tile[ 0 ] = floor( lbnd_out[ 0 ] ) + 1;
       lbnd_tile[ 1 ] = floor( lbnd_out[ 1 ] ) + 1;